We quantify intelligence (IQ), academic performance (grades), body weight (pounds or kilograms), running speed, and all sorts of other personal characteristics. But perhaps more useful than any of those numbers would be a measure of open-mindedness.

By "open-mindedness" we mean a genuine willingness to consider the evidence before rejecting an idea. We do not mean tolerance, or a rejection of absolute truth, or skepticism. Open-mindedness here means what the dictionary says: "receptive to arguments or ideas."[1]

One way to measure open-mindedness is to test for close-mindedness, and then take the converse. A subject for our measurement can be asked if he views certain proposals as impossible. By impossible we do not mean mathematically impossible, but so unlikely as to be considered absurd. Belief in impossibility is a sign of close-mindedness, because it reflects the unwillingness of the subject to be "receptive" to the possibility.

Test Your Open-mindedness

Do you resist admitting the possibility that a conservative approach to education is far more effective for students than a liberal one?

If it were proven to your satisfaction that some idea you've been using to bolster a political argument was false, would you keep using that idea in your argument?

Do you resist admitting that something you accepted for over a decade is, in fact, completely false?

Do you resist the possibility that Hollywood values result in significant harm for those who believe in them, and to innocent bystanders?

Do you think it is impossible that increased gun ownership reduces the rate of crime?

When President Ronald Reagan told Mr. Gorbachev to tear down the Berlin Wall, would you have thought that it was politically impossible for the Berlin Wall to be torn down?

Do you think that is impossible for the power of 2 in Newtonian gravity, whereby the gravitational force is proportional to 1/r2, to be more precise with an exponent that is slightly different from 2, such as a gravitational force proportional to 1/r2.00000001?

Do you resist admitting that some things taught to you in school are completely false, and even known to be false by some responsible for the material?

Do you deny that some widely required theories of science, such as the theory of evolution, may actually impede the progress of science?[3]

Do you deny that the imposition of socialism and same-sex marriage on a nation could harm its competitiveness at international events like the Olympics?

Do you refuse to consider the possibility that "experts" may not have all the answers, and that the best of the public may have valuable insights to which experts are blind?

Do you think that if you read parts of the Bible years ago as a child, you can claim to "have read the Bible" and that you have no reason to read it regularly now?

Do you believe that because the Earth's orbit and rotation are what they are now, they are guaranteed to remain stable for billions of years?

Do you refuse to consider the possibility that Hebrews might have been authored by Jesus?

The above questions can be asked, and one's closed-mindedness can be scored based on how often they answered "yes" above. Answering more than half as "yes" reflects acute closed-mindedness.

Follow-Up Questions

For each topic, a short set of follow-up questions is appropriate:

Have you seriously considered the evidence for this idea?

a. If no, then is that because you have never heard of it?

i. If if you have never heard of it, then will you seriously consider the evidence?

ii. If you have heard of it, but have never seriously considered the evidence, then on this question you lose a point for lack of open-mindedness.

b. If yes, then how much time have you spent reviewing the evidence? What evidence did you look at?

i. If less than 1 hour, then you lose a point for lack of open-mindedness.

ii. If more than 1 hour, then ... [Optional question: When, where, what and how did you review the evidence? If the answers are consistent with your claim of spending more than an hour, then ...] ... you gain a point for open-mindedness.

iii. If you have not reviewed the evidence due to lack of time or interest, have you formed an opinion about the idea anyway?

Further Refinements

A more sophisticated approach would be to replace the time threshold (an hour in the above example) with an analog version or formula that converted time spent reviewing the evidence of a new idea into a a variable for openmindedness. For example, the open-mindedness variable O could be:

where t is the time spent in minutes. O could then be summed over a series of topics, and normalized by dividing it by the number of topics.